The use of touch screens is rapidly growing in portable equipment. This equipment has extremely variable screen sizes from 2 inches to more than 12 inches in diagonal. The resolution of these screens is increasingly finer and is now comparable to that of conventional computer screens. This equipment relies on graphic interfaces with which the user will interact, for example using his/her fingers instead of a mouse to point, click, and select elements of the user interface.
One feature of this operating mode is that the pointing accuracy is low because the contact area of a finger on the interface is relatively great, in the order of ½ cm2. Generally, to compensate for this lack of accuracy, user interfaces are specifically designed for this equipment. Thus, buttons have greater dimensions than for a conventional computer and are more spaced on the user interface.
One function of these apparatuses is to replace a conventional computer for more and more numerous tasks and in particular Web access, writing messages (email), texts, etc. Therefore, situations occur in which applications designed for a conventional computer have to be supported or more simply Web sites designed for a conventional computer should be accessed.
In both cases, there is the problem of the pointing accuracy of the mouse. Different embodiments of a method for selecting an element of a user interface as well as different devices implementing such modes are known.
It is known the solution of Apple® implemented in the iPhone® for text editing areas where, to position the cursor, after pressing a finger on the screen for a long time, the area under the finger is reproduced zoomed above the finger. The user can, by moving his/her finger, position the cursor accurately. Accordingly, there is the problem of access on top of screen which is annoying when the virtual magnifier exits the screen. Besides, this method only operates with some applications. For example, an element of a Web site cannot be accurately pointed when it has not intended to implement such a solution.